1) (Japanese) What is the difference between da, desu, and de aru? And is there any rule as to when you use "mannaka (de)" or "naka (de)", or are they interchangeable? (The textbook I'm working from isn't absolutely clear on these.)
2) For a while I've been using
this reference book, since it's an immense help in looking up unfamiliar characters when I don't know their pronunciation. Now I'm wondering if there's any equivalent book available for Japanese-does anyone know if such a reference exists?